1. Field of the Invention
The present invention relates to a production process of a brush for a cosmetic tool such as a manicure or a writing instrument such as a brush-tip pen, which can contain an increased amount of a coating liquid, and uses of the brush do not specifically matter.
2. Description of the Related Art
A conventional production process for a brush which has so far been employed includes a process in which a suitable number of short fibers is set to a desired length and is tied up in a bundle and then the end parts thereof are put in order, and in which the rear end part thereof is bound by melting and then the tip part thereof is cut to an even face. In such a conventional process, a method in which all fibers are surely stuck to a melting end part is employed when monofilaments themselves are straight fibers, and therefore the work is complicated. In addition thereto, it is difficult to put the end part thereof in order, and the fibers which can not completely be stuck fall off, so that the number of fibers in the brush is scattered in a certain case. In the case of a brush in which monofilaments themselves are not straight fibers and comprise crimp fibers having twists, an opening formed between the fibers is enlarged as compared with that formed between the straight fibers, and it is very difficult to stick all fibers surely to the melting end part.
That is, crimp fibers are liable to get intertwined with each other due to twists thereof, and therefore when the end part of the respective fibers cut to a desired length is intended to be put in order in a state of a bundle, the intertwining of the fibers themselves makes it difficult to put the end part of the respective fibers in order. When the end part of a fiber bundle is bound by melting in such a state that the end part is not well put in order as described above, the fibers which are not stuck to the melting end part remain in the brush, and the problem that the fibers fall off from the brush is caused (refer to FIG. 1 and FIG. 12 attached), so that a fiber density of the brush is not stabilized and the brush which is not provided with a desired holding capacity of a coating liquid is obtained. Further, the fibers are insufficiently stuck, and therefore it is observed much often that the fibers fall off from the brush while applying a coating liquid.
In such conventional processes, not only in the case of crimp fibers but also in the case of straight fibers, there have been the problems in that it is difficult to process the tip part of a brush into a desired shape and scattering in a full length of fibers constituting the brush is caused and in that when a flange is disposed in the rear end part of the brush, it is difficult to form the flange in a required size without requiring an ancillary part, which allows the number of the parts to grow larger. An object of the present invention is to solve such problems as described above and to provide an efficient production process suited to a brush of a high quality, particularly a brush comprising crimp fibers in which an opening formed between the fibers is large and in which a quantity of a coating liquid held therein is increased.
The present invention has been as a result of various investigations continued in order to solve the problems described above and relates to a production process for a brush, comprising bundling parallel a prescribed number of fibers, temporarily binding the whole thereof by a resin or waxes (hereinafter referred to simply as resins) to form a long-size fiber bundle, cutting the above fiber bundle to a prescribed length, completely binding the tail end part of the cut fiber bundle and then dissolving and removing the resin present in the parts other than the finally bound end part to unbind the fibers.
That is, the present invention relates to a production process of a brush for a cosmetic tool or a writing instrument, comprising a consecutive combination of:
(a) a step of bundling a prescribed number of fibers into a desired diameter, applying a liquid resin or waxes at least on the peripheral surface thereof and then drying it to form a long-size fiber bundle in which the whole is temporarily bound,
(b) a step of cutting the temporarily bound long-size fiber bundle to a prescribed size,
(c) a step of completely binding the tail end part of the cut fiber bundle by a thermally fusing means in a state of fixing the fiber bundle, and
(d) a step of dipping the fiber bundle in which the tail end part is completely bound into a solvent capable of dissolving the resin or wax used in the step (a) described above to dissolve and remove the resin or wax adhered to unbind the fibers other than those in the tail end part of the fiber bundle, and if necessary,
a step of drying this fiber bundle after taking it out of the solvent.